Bed Bugs

Bed Bugs (Cimex lectularius) is a nocturnal parasite, feeds on mammalian blood, principally human but also dog, cat or rodents. Bites may cause an allergic reaction. Insects may be transferred on second hand furniture and bedding. Found mainly in hotels, guesthouses, hostels and B&B’s. They can be transferred on travel luggage. Infestations are not specific to poorer housing. There have also been legal actions take against hotels by residents experiencing bed bug bites.

Females lay up to 200 eggs attached to a structure in small numbers 4-5 times per day in crevices and harbourages. The use of central heating systems has expanded their widespread distribution with eggs hatching above 13°C. Resulting nymphs can moult about five times, averaging over about four months depending on temperatures and food supplies.


Emerging at night, all nymph stages feed on mammalian blood, feeding for about 10 minutes leaving a characteristic smell from their faeces and scent glands. Their bites leave an unpleasant irritation, red swelling on the skin and heavy infestations are characterised by their distinctive odour. They can ingest up to seven times their body weight in blood at any one meal time, however they can go for prolonged periods without feeding. Adults are highly resistant to starvation (up to one year) and low temperatures.


They may also crawl from room to room. Thoroughness is required when finding and treating harbourages. A flushing aerosol can be used to expose them in likely hiding places. Smears or spots may be visible on linen. Bed bugs can survive months without a host.


Bed frames, skirting boards, picture frames, headboards, bed frames, loose wall paper and wall switches with cracks or crevices are likely hiding places by day for bed bug nymphs or adults to shelter. Bedding materials including the mattress should be disposed off or heat sterilised (+ 60°C). Empty drawers or cupboards. All linen and clothing should be hot washed or professionally dry cleaned. Infested rooms should be treated at least 2-3 times to achieve successful control.


Voids under carpets should be treated by the pest control technician with professional insect growth regulator products. Clothing cannot be treated.  If problems persist a further survey at night using a pyrethrin’s aerosol may indicate harbourages that may have been missed. Bed bugs are difficult to control and costly to eradicate.

Mervyn WalshBA(Hons), HDip.EnvMgt, MRSPH

Field Conservation Biologist